Spring pressed overload release clutch



. R. K. JEFFREY l SPRING PRESSED OVERLOAD RELEASE CLUTCH Aug. 26, 1947.

Original Fild D90. 9, 1942 .//VL/f/Vme;

. QOBEQT K. JEFFREY,

DECEAsE, Y /SYFLOQENCEH-C-JEFFQ1 EXECUTa/X.

Patented ug. 26, 1947 SPRINGPRESSED OVER/LOAD RELEAS CLUTCH Robert K. Jeffrey,deceased,` late of Bexley,0hio, by Florence H. C. Jeffrey, executrix, Bexley, Ohio, assignor, by mesne assign1ne1its,to`The Jeffrey Manufacturing Company, a corporation of Ohio Original application December 9, 1942 Serial No.

Divided and this application March 30, 1944, Serial No. 528,720

(Cl. (i4-29) 1 Claim. 1

This invention relates to overload clutch mech-V anism for transferring a driving force from a gear or the like to a shaft or the equivalent; and an object of the invention is to provide an improved device of this class.

More particularly it is the object of the present invention to provide a spring-pressed slip clutch associated with power-transmission mechanism, and an anchorage on a supporting frame so as to relieve such poweritransmission mechanism of pressure exerted by the spring of such clutch.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claim.

In the accompanying drawings,

Fig. 1 is a sectional elevation of mining machine kerfcutter driving mechanism connected by means of power transmission mechanism to cuttings removal mechanism and embodying my improvements;

Fig. 2 is a sectional elevation taken on the line 2 2 of Fig. 1, looking in the direction of the arrows; and

Fig. 3 is a fragmentary sectional elevation taken transversely of the right-hand end portion of Fig, 1. Y

This application is a division of the co-pending application, Serial No. 468,398, filed December 9, 1942, now Patent Number 2,359,422, issued October 3, 1944, for an improvement in Mechanism for removing cuttings from the kerf cutter of a mining machine.

In the accompanying drawings, the improved clutch of my invention is illustrated as connected in a gear train of a mining machine and provides a slip clutch drive for cuttings removal mechanism I which is adapted to be detachably connected by means of cap lscrews I4 to the main frame I I of a mining machine which includes the chain kerf cutter I2, only a portion of the complete mining machinev being shown. In Fig. 2 the supporting frame of the cuttings removal mechanism is Vdesignated I0 and this framemay be `welded to the extension I3 which is adapted to t against the bottom plate II', Vbeing held there by the cap vscrewV I4 extending through the depending bracket I5 and threaded into the eX- tension I3. The frame I0 may be thus detachably secured to the plate I AI at a pluralityof spaced-apart points.

The chain kerf cutter I2 comprises a chain I1 provided with bits I8 and is adapted to be driven by `an electric motor connected to the worm gear 23. The latter is mounted on the roller bearing 24 `concentric with the vertical shaft 25. Connection ofthe worm gear 23 to the vertical shaft 25 may be controlled by means of a suitable clutch (not shown).

As shown in Fig. l,` the vertical shaft Z5 is journaled by means of the roller thrust bearings 32 Aand 33 to the tubularsupport 34 which is secured to the frame II Vof the mining machine by means of cap screws 35. A `retaining ring 36 is secured to the tubular support 34 by means of cap` screws to hold theV thrust bearings 32, 33 in adjusted positions.

Keyed to the vertical shaft 25 is a spur gear 59 as shown inFig. 1. This spur gear 59 meshes with a larger spur gear 6l] which is journaled on a vertical bearing I The gear 60 in turn meshes with a gear 62 journaled on the bearing E3, and the gear 62 meshes `with the dished gear E4 which is concentric withthe vertical shaft 65. The gears 59, 60, 62, and 64 are all preferably in the same horizontal plane. Gear 64 constitutes the power transferring or driving member of `an overload releasingclutch of which shaft 65 is the driven or second power transferring member.

Secured to the spur gear' 64 is a bushing 66 which is journaled loosely `onl the vertical shaft 65. AKeyed to the upper portion of the shaft 65 and slightly slidably `mounted thereon is a quill shaft or sleeve 61 the lower end of which is provided witha circular or annular extension til forming a spring abutment and having on the bottom thereof and near the periphery, a series of circularly arranged recesses 69 for receiving the balls 1D, 19. These balls 10,10 extend through a series of circularly arranged openings in the upper'horizontal portionnr web of the dis-hed gear E54` and contactwith the top of the thrust ring l! which encircles the hub 'i2 of the gear 5a, and is housed withinthedished gear 364 as shown in Fig. 1. The ring II is V,supported by means of the ball thrust bearinglS on the annular support 1-4 which extends upwardly from the annular fran-remember 15. By `mean-s of a vseries of circumferentially spaced cap screws 16, the annular member 'l5 is securedy rigidly to the frame II of the mining machine and forms a part thereof,

The upper end of the shaft 65 has a reduced extension journaled by means of the ball bearing F8 in the horizontal upper plate '|9 of the mining machine frame. Lubricating means 89 may be provided at the upper end of the shaft extension 11,

J ournaled on the shaft extension and resting on the annular shoulder 8| is a ring shaped cup or cap 82 for receiving the upper end of a helical compression spring 83, the lower end of which rests in an annular recess on top of the slidable abutment member 68.

The shaft 65 drives a cuttings removal mechanism, which will now be described, it being understood that said cuttings removal mechanism is only one illustration of the type of device which may be driven by my improved clutch.

The lower end of the vertical shaft 65 is provided with a circular plate 84 which fits into the ring 85. Between the lower end of the shaft 65 at the top of the plate 84 and the supporting ring 'l5 is a ball bearing 86. A circular lubricant sealing ring 8`| intervenes the upper central portion of the plate 84' and the ring 15.

The ring 85 has welded thereto at 88 a cylinder 89, the lower end of which is open and located closely adjacent the inner upper surface of the plate I9' forming a part of the supporting frame of the cuttings removal mechanism. By means of cap screws 99, 99 extending through the ring sections 9| and threaded into the circular plate 84, the ring 85 is supported at the annular recess 92. In other words, the inner annular recess in the ring 85 at 92 co-operates with the periphery of the ring 84 to form a groove for receiving the annular upwardly extending extensions from the ring sections 9|.

The cylinder 89 and the mechanism for supporting the same constitutes a drum closed at the top by the plate 84 which rotates therewith and closed at its bottom by the relatively stationary plate |9. The cylinder 89 is provided with four vertical slots spaced apart 99 from each other. Extending through these vertical slots are flights 93 and 94. The flight 93 is provided with an elongated opening 95 of sufllcient length to have extended therethrough the other flight 94 when held in a horizontal position. The flight 94 has a central portion 94 adapted to move freely back and forth through the opening 95 when the flight 94 is vertical.

Riveted to the bottom plate I9', as shown in Fig. 1, is a cam 96 having an approximately elliptical shape. Each of the flights 93 and 94 is provided with cut-away portions to provide inner opposing curved edges for engaging the periphery of the cam 96. The flight plate 93 is provided with the lower opposing curved engaging edges for engaging opposite sides of the cam 96. The flight 94 is provided with lower inner oppositely facing curved edges lfor engaging opposite faces of the cam 96. It should be noted that in the periphery of the cylinder 89 of the drum are located guiding plates |9|, |9| for one end portion of the flight 93, and guide plates |92, |92 for the other end portion of the flight 93. In a similar manner, guide plates |93, |93 are provided for one end portion of the flight 94, and plates |94, |94

for the other end portion of the flight 94. Eachv of the guide plates may be welded at their outer vertical edges to the edges of the vertical slots in the cylinder 89, and these guide plates may be wider at their upper ends than at their lower ends, as indicated by the dotted lines in Figs. .1 and 2.

A vertical deflector plate |01 welded to the frame of the mining machine has the shape of a segment of a cylinder and extends vertically from the bottom plate I9 in a position close to the path of travel of the outer end of each of the flights. Consequently the flights 93 and 94 are extended to a maximum extent when closest to the chain cutter. As each flight continues to rotate, it acts positively on the cuttings to sweep them rearwardly and off the bottom plate I9. At the same time each flight recedes into the drum as it approaches the abutment |98, the inner surface of which at |99, has the shape of a segment of a cylinder concentric with the cylinder 89 or the axis of rotation of the drum. It will thus be seen that the periphery of the cylinder 89 may be located in close proximity to the inner surface |99 of the abutment |96. 'Ihe height of the abutment |98 is approximately coextensive with the height of each of the flights 93 and 94. Consequently practically no cuttings will be carried past the abutment |98 back toward the kerf cutter. Furthermore, the vertical edge I9 of the abutment |93 may be sufficiently sharp to scrape from the outer surface of the cylinder 89 such material as may be clinging thereto. Moreover, the flights may have a sufficient fit between the plates along which they slide that such material as may cling to the outer surfaces of the flights may be wiped off when the flights recede into the drum. I

If either flight 93 or 94 should meet an obstruction which might cause part of the mechanism to break, the spring 83 will be compressed intermittently as the plate 68 travels over the balls 19, 'i9 and gives the signal by the noise produced that the operation of the machine should be discontinued andthe obstruction removed.

It should be particularly noted that by reason of the flights 93 and 94 being projected from diametrically opposite sides of the drum cylinder 99, the rapidity of the sweeping of the cuttings is sufcient to render the cuttings removing mechanism so eillcient that during each half rotation of the drum the cuttings are removed and deposited where the tendency is reduced to a minimum for the coal cuttings to be Ymoved back toward the kerf cutter. That is to say, instead of having each flight extend outwardly to a maximum extent once during each rotation of the drum, it is extended out from the drum to a maximum extent twice during each rotation of the drum. By referring to Fig. 1 it can be seen that while the right-hand end of the flight 93 is moving through 189, the other end is at the same time moving through only .to reach its maximum projection from the drum. Thus the capacity for removing cuttings is increased two-fold by having the opposite ends of each flight project from the drum and each acting to take the place of the other during each 180 of rotation of the drum cylinder 89.

The flights 93 and 94 may rest by gravity partly on the'upper surface of the plate I9 and partly on the upper surface of the cam plate 96, but it is preferred to space those portions of the flights 93, 94 that overhang the cam 96, slightly from the upper surface of the plate i9 and have the flights restv by gravity onthe upper surface of the camV 96 since the latter is always inside the cylinder 39 and therefore relatively free from cuttings or foreign material. The flights 93 and 94 are therefore supported on the upper surface of the cam' 96 and can slide freely thereon when rotated since such upper surface is much cleaner than the uppersurfae of the plate Ill.

However, the lower edge of the cylinder 89 is in close proximity to the plate I0 andthe flights 93, 94 flt closely in the slots iii-this cylinder The cylinder, constitutes a cylindrical abutment, or the drum above `referred to may be consideredwthe rotating abutment, whereas` the abutment i919 is stationary.

It should be particularly noted that if `the ights 93, 99 become Worn they may readily be renewed after detaching the plate Ill from the frame of the mining machine, by removing the plurality of cap screws.

l Since the slots in which the flights 93, 99 are slidable are open at their lower ends, these flights canreadily be permitted to drop out from the drum'cylinder 89 without removing the cap screws 99, 9D., When the nights have been removed they may be taken apart by rotating one 90 relatively to the other 4so 'that the flight 94 may be moved outfof the opening 495. When assembling a new pair of ights they are first placed at right angles to each other and then moved upwardly into the slots in the cylinder 89 and the cam 9S replaced by securing the plate I9' to the mining machine frame. The flights are then again interlocked lby the. slots in the cylinder 89 and each flight may be recipreoated freely in its own plane without interference from the other, on account of the narrow portion 94 of flight 911 extending through the elongated or rectangular opening 95 in the `flight 93.

Reverting to the ball clutch, it should be noted that the downward thrust of the spring 93 is eXn erted through the clutch balls 1B and ball thrust bearing 13 onto the annulation 14 of the annular supporting member that is secured rigidly to and forms a part of the frame of the mining machine. The gear 94 is thus relieved of the thrust from` the spring 83 and when the gear 94 rotates the ball clutch mechanism rotates therewith as a unit with the ball bearing 13 at the lower end of such unit and the ball bearing 18 at the upper end thereof.

It should be particularly noted that when the ground engaging pan I9 is detached by removing the various screws i4, one of which is shown in Fig. 3, the elliptical cam 96 is separated from the flights 93, 94 so that the latter may be removed from the drum S9 by sliding them out of the slots in the latter since these slots are open at their lower ends.

The ring 85 together with the drum 89 may be disconnected from the disc 94 by removing the screws 99, 99. Welded to the bottom plate Il of the main frame Il is a supporting ring 111'. The diameter of the opening in this ring 14 is greater than the diameter of the gear GII and consequently when the supporting screws 19, 16 are removed from the ring 1li', the entire slip clutch unit may be dropped out of the interior Vof the frame Il through the ring 1li'.

When the apparatus shown in Figs. l and 2 is to be reassembled, the gear 9d is rst brought back into mesh with the gear 92 by fitting the annular supporting member 'I5 into re-engage ment with the ring 14' whereupon the screws 15, 19 are reinserted to hold the parts in assembled relation with the gear 92 in mesh with the gear Ell The downward force exerted by the spring B3 will then be resisted by ring 'It which is nov; rigidly connected to the main frame II.

The ring 95 Iand the drum 89 may then be reassembled in connection with the disc 94 by rcplacing the screws 90, 90. Now` by placingthe nights 93,. 94A in rightfangled relation, they may beslid into-theslots in the Vdrum 89. Finally the cam 99 may be Vbroughtinto `engagement with theilights 95, 94 by replacing the screws lflgto connect thelpanjlilTto the `main frame il., l 1t will thus beV seen that whenthe slip clutch Vunit and the parts associated therewith are assembled, the lflights 93, Sid-will rest on the cam. 96'for supp ort thereby, and the Vdrum 89 being rigidly connected to the shaft 65 may -bearranged to be supported by theball bearings 'I8` and 86.- I

The upper end of the spring 83 presses against an abutment provided by the shallow cup; 82 which in` turn abuts against the inner race of the ball bearing 18. The upper extension 11 of the shaft 95 is of reduced diameter to afford the annular shoulder 9| engaged by the cupy82.V The shaft extension 11 is screw-threaded at its upper end to receive the nut IIS which may be relied on to keep theinner race of the ball bearingl in yplace on the extension v11 by clamping this inner race against thecup- B2 and 'thevr latter against theshoulder 8 I and thus rigidly secured to shelfm- The upward thrust on shaft 65 imparted by spring 83 is transferred to the annular supporting member 15 of the frame I I through the bearing 39, the upper edge of fthe outer race of which abuts a shoulder thereof.

Downward pressure or thrust of the spring 83 is against the pressure plate or disc 68 and thence through the circumferential spaced balls 19 through the top openings in the gear 94 onto the ring 1I to the ball thrust bearing 13 being ultimately taken by support 'I4 and frame member 15. When the kerf cutter I2 is driven, the gears 59,' 60, 62 and 94 are operated to rotate the gear GII, which, except for the clutch member, is mounted loosely on the vertical shaft B5. The balls 19 fitting in the recesses 99 transmit rotary movement from the gear 64 to the pressure plate or disc E8 which is integral with the sleeve 61. Since the sleeve 61 is keyed at H1, H1 to the shaft 65, the latter will be rotated when the pressure plate or disc 58 is rotated.

It will thus be seen that the lower end of the spring 83 is seated on the main frame by means of the balls 19, the ring 1I, the ball thrust bearing 13, annular supporting member 15 and the ring supports 14, 14. The upper end of the spring is seated against the cup 82. Cup 82 is rigidly attached to shaft 65 and the upward thrust of spring 83 is transferred through shaft 65 and bearing 35 to frame member 15, as previously set forth.

The shaft and fthe parts carried thereby being thus resiliently supported on the main frame, the stresses and strains on the ball bearings 'I8 and 89 during operation of the cuttings removal mechanism, may be reduced to a minimum to free the latter sufciently to greatly facilitate rotation of the shaft 65.

By removing the screws 16, 16 from the ring support 14', the shaft 65 and the parts associated therewith may be removed as a unit. That is to say, the assembly of the shaft 65, the disc 35, the ring support 1d, the ball bearing 85, the gear 94, the slip clutch and the supports for the latter may be removed from the supporting frame II as a unit, by sliding the outer race of the ball bearing from the plate 19 and by sliding the gear 64 out of mesh with the gear 62, the diameter of the opening in the ring 14' being suilcient for this purpose. Such removal of this Obviously those skilled in the art may make 5 various changes in the details `and arrangement of parts without departing from-the spirit and scope of the invention as dened by the claim hereto appended, and it is therefore preferred not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodi- .ment of the invention, what it is desired to secure ,by Letters Patent of the United States is:

In a device of the class described, the combination with a shaft, of a gear journaled on said shaft, a spring-pressed slip clutch connecting :said gear and said shaft and including thrust :means acting on a series of circumferentially lspaced balls extending through openings in said gear, a support for said shaft, and means for re- -ceiving the'thrust through said balls and transferring it to said support.

FLORENCE H. C. JEFFREY, Eecutria: of the Estate of Robert K. Jeirey,

Deceased.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,877,440 Adatte Sept. 13, 1932 865,486 Gannon Sept. 10, 1907 10 2,278,119 Richards Mar. 31, 1942 2,320,004 McCullough May 25, 1943 2,268,260 Mavor Dec. 30, 1941 2,320,307 Saville May 25, 1943 1,883,164 Vassakos Oct. 18, 1932 15 1,904,375 Kind April 18, 1933 2,072,924 Smyth, Jr. Mar. 9, 1937 2,291,407 Paul July 28, 1942 FOREIGN PATENTS 20 Number Country Date 37,763 France 1931 

